Experimental study on configuration optimization of floating breakwaters

In this paper, four types of floating breakwaters (FB) are proposed: cylindrical floating breakwater (CFB), porous floating breakwater (PFB), mesh cage floating breakwater type-I (MCFB-I) and mesh cage floating breakwater type-II (MCFB-II). The hydrodynamic performance of each type has been tested to identify the most effective configuration for wave attenuation. The experiment was conducted in a wave flume in which regular waves were produced. The incident and transmitted waves, the tensions in the mooring lines and the motion responses of all of the four types of floating breakwaters were measured. It is shown that all proposed types of floating breakwaters can effectively reduce transmitted wave amplitude. Among them the MCFB-I is seen to yield the most attenuating effect on incident wave amplitude

Recombination frequencies between cultivated soybean (Glycine max) and its wild relative Glycine soja based on molecular marker analysis

Close relatives of cultivated crops provide an invaluable source of genetic variation in crop improvement and exploiting such variation often forms a critical part in a breeding program. The usability of the wild soybean Glycine soja was investigated in this study by analyzing populations derived from two wide crosses between a common cultivar and two different G. soja accessions using simple sequence repeat (SSR) markers. Consistent reductions in recombination frequencies were not detected in either of these two wide crosses and the results does not seem to be confined to the particular populations or the wild genotypes used. In variance with previous reports that domestication-related traits are often controlled by one or two major loci, these recombination results strongly indicate that linkage drag should not be a major concern in transferring genes from the wild taxon into the cultigen, although backcross would still be required to minimize undesirable chromatins.Keywords: Glycine max, Glycine soja, linkage drags, recombination frequency, molecular markersAfrican Journal of Biotechnology Vol. 12(22), pp. 3522-352

Experimental study of a new type of floating breakwater

A new type of floating breakwater (FB) is proposed in this paper. Its hydrodynamic performance has been tested. The structure of the new breakwater named cylindrical floating breakwater (CFB) consists of two parts: a main body of rigid cylinders, and a flexible mesh cage containing a number of suspending balls that are intended to absorb the wave energy into their mechanical energy. A series of experiments were carried out on the new floating breakwater and traditional double pontoons and box floating breakwaters to compare their performances. A two-dimensional wave flume was used in the experiment; the incident and transmitted waves, the tensions on the mooring lines and the motion responses of the floating breakwaters were measured. Results showed that the new floating breakwater had a better performance than the traditional double pontoons and the box floating breakwaters: wave transmission was significantly reduced by the mesh cage with the balls, especially for long waves

Theoretical and numerical estimation of ship-to-ship hydrodynamic interaction effects

The main objective of this paper is to investigate theoretically and numerically how much interactions are expected between two ships travelling in waves. The theoretical estimation is based on asymptotic far-field wave patterns produced by a translating and oscillating source. The far-field wave pattern is governed by the parameter τ=ωeu0/g; For values of the parameter τ>0.25 there exist a fan-shaped quiescent region in front of the vessel. As τ increases, the range of the fan-shaped quiescent region will be expanded. The critical line between the quiescent and wake region can be estimated by the asymptotic expressions theoretically. It is expected that there is no hydrodynamic interaction if the two ships are located in each other's fan-shaped quiescent region. But due to the near-field local waves produced by the 3-D ships, the critical line could be different from that estimated from asymptotic wave pattern. Therefore, we developed a 3-D panel method based on Rankine-type Green function to investigate the hydrodynamic interaction effects for several combinations of parameters, including oscillation frequency, forward speed and transverse distance between two ships. Finally, the critical line calculated numerically was presented and compared to the theoretical estimation

3D experimental study on a cylindrical floating breakwater system

The objective of the present study is to investigate the performance of a cylindrical floating breakwater system based on 3D experimental tests. The experiments were carried out in the wave basin (36 m*60 m*1.5 m)of the Ocean University of China. The cylindrical floating breakwater system consists of 10cylindrical floating breakwater units and 10mesh cages with balls in them, connected by 18 connectors and moored by a taut mooring system. The wave transmission coefficients, reflection coefficients, dissipation coefficients and motion responses of the floating breakwater are measured in both oblique and beam sea conditions. It is found that with the increase of the wavelength, both of the wave transmission coefficients and motion response amplitude of the FB system suffers an increase before it reaches its peak value, followed by a decrease trend. It can be concluded from the experiments that the proposed FB system has a satisfactory performance and it can be used to a wide range of sea conditions

Biochemical and transcriptomic analyses reveal different metabolite biosynthesis profiles among three color and developmental stages in ‘Anji Baicha’ (Camellia sinensis)

Primers used for quantitative reverse transcription polymerase chain reaction analyses. (XLSX 11 kb

A Novel Selective Ensemble Algorithm for Imbalanced Data Classification Based on Exploratory Undersampling

Learning with imbalanced data is one of the emergent challenging tasks in machine learning. Recently, ensemble learning has arisen as an effective solution to class imbalance problems. The combination of bagging and boosting with data preprocessing resampling, namely, the simplest and accurate exploratory undersampling, has become the most popular method for imbalanced data classification. In this paper, we propose a novel selective ensemble construction method based on exploratory undersampling, RotEasy, with the advantage of improving storage requirement and computational efficiency by ensemble pruning technology. Our methodology aims to enhance the diversity between individual classifiers through feature extraction and diversity regularized ensemble pruning. We made a comprehensive comparison between our method and some state-of-the-art imbalanced learning methods. Experimental results on 20 real-world imbalanced data sets show that RotEasy possesses a significant increase in performance, contrasted by a nonparametric statistical test and various evaluation criteria

Abnormal diastolic function underlies the different beneficial effects of cardiac resynchronization therapy on ischemic and non-ischemic cardiomyopathy

OBJECTIVES: To investigate the association between diastolic function and the different beneficial effects of cardiac resynchronization therapy in patients with heart failure due to different causes. METHODS: The 104 enrolled patients were divided into an ischemic cardiomyopathy group (n=27) and a non-ischemic cardiomyopathy group (n=77) according to the cause of heart failure. Before implantation, left ventricular diastolic function was evaluated in all patients using echocardiography. After six months of follow-up, the beneficial effects of cardiac resynchronization therapy were evaluated using a combination of clinical symptoms and echocardiography parameters. RESULTS: The ischemic cardiomyopathy group included significantly more patients with restrictive filling than the non-ischemic cardiomyopathy group. The response rate after the implantation procedure was significantly higher in the non-ischemic cardiomyopathy group than in the ischemic cardiomyopathy group. Degrees of improvement in echocardiography parameters were significantly greater in the non-ischemic cardiomyopathy group than in the ischemic cardiomyopathy group. Multivariate regression analysis showed that a restrictive filling pattern was an independent factor that influenced responses to cardiac resynchronization therapy. CONCLUSIONS: This study again confirmed that the etiology of heart failure affects the beneficial effects of cardiac resynchronization therapy and a lower degree of improvement in ventricular systolic function and remodelling was observed in ischemic cardiomyopathy patients than in non-ischemic cardiomyopathy patients. In addition, systolic heart failure patients with severe diastolic dysfunction had poor responses to cardiac resynchronization therapy. Ischemic cardiomyopathy patients exhibited more severe diastolic dysfunction than non-ischemic cardiomyopathy patients, which may be a reason for the reduced beneficial effect of cardiac resynchronization therapy